Re: Most efficient method of simplifying
- To: mathgroup at smc.vnet.net
- Subject: [mg16215] Re: [mg16187] Most efficient method of simplifying
- From: Richard Gass <gass at physics.uc.edu>
- Date: Fri, 5 Mar 1999 00:40:47 -0500
- Sender: owner-wri-mathgroup at wolfram.com
>Hello all: > >I realize this is not a well defined questions, but I'm working with some >fairly nasty ratios of functions (generally ratios of polynomials, but not >always). At several points I do some substitutions and then I want to >simplify the result such that (1) all variables are removed (cancelled) that >can be, and (2) the result simplifies to zero if appropriate. > >"Simplify" is the obvious choice, but I've had many cases where simplify did >not cancel and/or find the zero solution. So, I could use FullSimplify, but >both versions can take days to run. All I really need is to "expand", but >again there are cases where expand doesn't cancel and/or produce the zero >result. "ExpandAll" can make even the simpliest expression exremely >complicated. > >So, I'm looking for any advice others may have for more efficient ways of >doing Simplify[ Expand[ ]]. As I said, this is not a well defined question >& I suppose the ultimate answer is to use FullSimplify and buy the largest >computer available. > >Thanks, > >Greg Geg I have had very good luck on large expressions by first using Together and then Simplify. In addition to getting a simpler result this has cut computation time down from days to minutes in some cases Richard Gass Department of Physics University of Cincinnati Cincinnati, OH 45221 phone- 513-556-0519 E-Mail gass at physics.uc.edu